Window Wells: Covers and Drainage

Your window well is doing one of two things right now: protecting your basement, or slowly destroying it. There is no middle ground.

In Toronto, window wells collect everything the sky throws at them. Snow. Freezing rain. Leaves from that silver maple your neighbour refuses to trim. A dead squirrel, occasionally. Without a cover and proper drainage, all of that ends up sitting in a concrete-lined pit pressed directly against your foundation wall.

And Toronto's clay soil is not going to help you drain it.

Why Window Wells Exist (And Why They Fail)

A window well is a semi-circular or rectangular excavation around a below-grade window. It holds back the earth, creates an air pocket for light and ventilation, and — for egress windows — provides a path out during an emergency.

The problem is gravity. Water runs downhill, and your window well is the lowest point next to your foundation. Every square foot of ground sloping toward that well is funneling water straight into it.

The Toronto Factor

Most of Toronto sits on Halton Till — heavy clay soil that absorbs water slowly and releases it even slower. When spring melt hits or a summer downpour dumps 30 mm in an hour, that clay becomes saturated. The water has nowhere to go except sideways, into your window well.

This is why drainage matters more than the cover. A cover keeps the direct rain out. But groundwater pressure from saturated clay will still push moisture toward the well from below and from the sides. You need both systems working together.

Window Well Covers: The Three Types That Actually Matter

1. Clear Polycarbonate (Flat or Sloped)

This is what we recommend for most GTA homes. Here is why.

Polycarbonate transmits roughly 90% of visible light. Your basement stays bright. The solid surface keeps out rain, snow, leaves, and wildlife. Custom units with aluminum frames hold up to 400 lbs — more than enough for a Toronto winter's worth of snow stacked on top.

Sloped versions are better than flat ones. Snow slides off. Water sheets away from the foundation instead of pooling.

Cost: Stock sizes start around $49 at building centres. Custom-fitted polycarbonate covers with aluminum frames run $150-$400 per well, depending on dimensions.

The catch: Polycarbonate is not a walking surface. If your well is next to a walkway or patio where people step, this is not the right choice.

2. Metal Grates

Metal grates are the brute-force option. They handle foot traffic, snow load, and the occasional delivery driver who cuts across your lawn.

The trade-off is everything else. Grates block 30-40% of natural light. They let rain, snow, leaves, and debris fall straight through into the well. They do nothing for drainage — they are just a safety barrier, not a weather barrier.

They also rust. Even powder-coated steel grates in the GTA start showing corrosion after 8-10 years unless maintained.

When grates make sense: Walkable areas, commercial properties, wells next to driveways. Not for a bedroom egress window where you want light and weather protection.

3. Bubble (Dome) Covers

Bubble covers are the compromise option. The dome shape sheds snow and rain well, and polycarbonate construction lets light through. They hold around 150 lbs.

The downside: They yellow. UV exposure degrades the polycarbonate over 5-8 years, and the dome shape makes them look dated fast. They also protrude above grade, which creates a trip hazard and makes lawn maintenance annoying.

We install them when asked. We do not recommend them as a first choice.

Drainage: The Part Everyone Skips

A window well cover without drainage is like putting a lid on a pot of boiling water. It slows things down, but the pressure is still building underneath.

What Proper Drainage Looks Like

Here is the system that actually works in Toronto soil:

1. 4-inch vertical drain pipe from the bottom of the well, connected directly to your home's perimeter weeping tile system.
2. 8 inches of 3/4-inch clear stone on top of the drain. Not pea gravel. Not crushed limestone. Clear stone — it does not compact and maintains drainage channels.
3. Filter fabric between the stone and the surrounding soil to keep silt from migrating in and clogging the stone.
4. Proper grading around the well exterior so surface water flows away from the foundation, not toward it.

The $200 Mistake

The most common DIY approach: throw a few inches of gravel in the bottom of the well, slap on a plastic cover from the hardware store, and call it done.

It works for a year or two. Then the gravel clogs with silt and organic debris. The cover traps moisture inside the well because there is no airflow. Condensation builds. The well becomes a humid pocket against your foundation wall, and you start seeing mould on the interior basement wall.

If you are not connecting to weeping tile, the gravel is decorative. It is not drainage.

When Wells Flood Anyway

Even a properly drained well can flood if the weeping tile itself is compromised. In Toronto homes built before 1970, the original clay or concrete weeping tile may be collapsed, root-invaded, or simply full of silt after 50+ years.

If your well fills during every heavy rain despite having a drain, the problem is downstream. You need a camera inspection of the weeping tile — not another bag of gravel.

Ontario Building Code: What the Inspector Checks

The 2024 Ontario Building Code (in effect since April 2025) has specific rules about window wells. Here is what matters for homeowners.

Egress Requirements

If the well serves a bedroom egress window:

• Opening size: Minimum 0.35 m² (3.8 sq. ft.) with no dimension less than 380 mm (15 inches).
• Well clearance: 550 mm (22 inches) of clear space in front of the window when open.
• Deep wells: Wells deeper than 1 metre require permanent steps or a ladder affixed to the wall.
• No tools: The window must open from inside without keys, tools, or special knowledge.

Cover Rules

This is the part people miss:

• If you install a cover on an egress well, it must be openable from inside the well without tools. A cover screwed down with lag bolts fails code.
• The cover cannot reduce the required clearance below 550 mm.
• The cover must not prevent a person from exiting through the window in an emergency.

In practice, this means your cover needs a hinge or a lift-off design. Most quality polycarbonate covers use a clip system that releases with hand pressure from below. Metal grates are typically heavy enough to require lifting — which is legal, but barely practical for some people.

Installation: What We Do Differently

At Installix, we see a lot of window wells that were installed as an afterthought. The well is there. The window is there. But the connection between them — the drainage, the seal to the foundation, the cover — was never done properly.

The Common Failures We Fix

• Wells not fastened to the foundation wall. Toronto's freeze-thaw cycle heaves the soil. An unanchored well gradually lifts away from the wall, and soil migrates underneath, blocking the drain.
• No drain connection. The well has gravel but no pipe to the weeping tile. It is a puddle with decorative rocks.
• Wrong cover type. A flat, unsealed cover that pools water on top and drips it into the well through the edges.
• Undersized wells for egress. The window meets code, but the well does not provide 550 mm of clearance. The inspector fails the whole assembly.

What a Proper Install Includes

When we install or retrofit a window well, the scope covers:

1. Excavation to below the window sill
2. Well anchored to the foundation with masonry fasteners
3. Waterproof membrane between the well and the foundation wall
4. 4-inch drain tied to the perimeter weeping tile
5. 8 inches of clear stone fill
6. Custom-fitted polycarbonate cover with aluminum frame
7. Grading correction around the well perimeter

The whole job takes a day per well. For basement window installations, we handle the well as part of the window project — not as a separate trade.

When to Replace vs. Repair

Replace the cover if:

• It is yellowed, cracked, or no longer sits flush
• It is a bubble dome that has lost its shape
• You upgraded to a larger egress window and the old cover does not fit

Replace the drainage if:

• Water pools in the well after moderate rain
• You see standing water in the well 24+ hours after the rain stops
• The interior basement wall near the window shows water stains or mould

Replace the entire well if:

• It has separated from the foundation wall
• It is rusted through (steel wells in pre-1980 homes)
• It does not meet current egress clearance requirements after a window replacement

Seasonal Maintenance for Toronto Homeowners

Fall (October-November):

• Clear all leaves and debris from the well
• Check the drain by pouring a bucket of water in — it should drain within 5 minutes
• Inspect the cover for cracks or broken clips

Spring (March-April):

• Remove any remaining snow or ice from the well
• Check that the cover has not shifted during freeze-thaw
• Verify the well has not heaved away from the foundation wall
• Test the drain again before spring rains hit

After any major storm:

• Walk the perimeter. If a well is holding water, something is blocked.

This is a 15-minute walk-around. It prevents a $5,000-$15,000 basement flood repair.

The Bottom Line

A window well is a simple thing — a hole in the ground next to your foundation. But in Toronto's clay soil, with our freeze-thaw cycles and increasingly heavy rainfall events, a neglected well is a direct path to basement water damage.

The fix is not complicated: a proper drain to the weeping tile, clear stone fill, and a fitted polycarbonate cover that lets light in and keeps everything else out. Total cost per well runs $300-$800 installed, depending on whether you need drainage work or just a cover.

Compare that to the average Toronto basement flood claim. It is not close.

If your wells need attention — or you are planning a basement egress window project and want the wells done right the first time — reach out for a quote. We will measure, assess the drainage, and give you a straight answer on what your wells actually need.

Frequently Asked Questions

Do window well covers block natural light? Metal grates block 30-40% of light and are mostly used for walkable surfaces. Clear polycarbonate covers transmit about 90% of light — your basement stays bright. Bubble-dome covers perform similarly but can yellow after 5-8 years of UV exposure.

Can I just put gravel in the bottom of my window well instead of connecting to weeping tile? You can, and it will work for about two years. Then silt and debris clog the gravel, and you have a non-draining basin holding water against your foundation wall. In Toronto's clay soil, that water has nowhere else to go. Proper drainage means a 4-inch vertical drain line connected to your perimeter weeping tile, topped with 8 inches of 3/4-inch clear stone.

Does the Ontario Building Code require window well covers? The OBC does not mandate covers on all window wells. However, if you install a cover on an egress window well, it must be openable from inside the well without tools or special knowledge. Many Toronto homeowners add covers voluntarily to prevent flooding, debris buildup, and falls.

How much weight can a polycarbonate window well cover hold? Custom low-profile polycarbonate covers with aluminum frames are typically rated to 400 lbs, which handles Toronto snow loads easily. Standard bubble covers hold around 150 lbs. Neither type is rated as a walking surface — if you need foot traffic, you need a steel grate.

How often should I clean my window well drain? Twice a year minimum — once in late fall after leaves drop, and once in early spring before snowmelt. In practice, most Toronto homeowners forget until they see water pooling. If your well fills during a rainstorm, the drain is already partially blocked.